Contact device



Jan. 24, 1928. 1,657,235

E. v. SUNDT CONTACT DEVICE Filed NOV- 10. 1925 l II //7 Van for dim/d M50/74? Patented 24, 1928.

UNITED' STATES PATENT OFFICE.

EDWARD VICTOR SUNDT, OF CHICAGO, ILLINOIS, ASSIGNOR TO WESTERN ELECTRICCOMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

. CONTACT. DEVICE.

Application filed November 10, 1925. Serial No. 68,156.

This invention relates to contact devices, and has for its primaryobject the provision of a simple, durable and inexpensive contactdevice, wherein electrical connection is effected with fragileelectrical conducting elements in an expeditious manner.

The present invention contemplates a contact device having areciprocally mounted element, which is moved, when it is desired 10 tocomplete an electrical circuit and which, due to its movement, displacesa conducting fluid such as mercury, into electrical contact with ametallic element in circuit connection with apparatus to be associatedwith 15 the electrical circuit.

At various stages in the process of manufacturing telephone switchboardlamps and the like, it is sometimes necessary to energize the lampfilament'for the purpose of treating 20 or testing. Thus, for example,in the process of manufacturing tungsten lamps, it is desirable todeoxidize the tungsten filament prior to sealing a cap or bulb over thefilament. This reduction process is accomplish- 26 ed by'subjecting thefilament, which is embedded at the upper end of a glass lamp stem,

to instantaneous incandescense in an atmosphere of hydrogen. Certainmethods now employed to connect each filament with an 80 electricalcircuit prior to the above mentioned treatment, require the terminalsthereof to be gripped by certain types of mechanical connector elements.These methods require the exercise of a considerable degree of skill inorder to prevent distortion or injury of the filament which is verdelicate in structure and easily damaged y any appreciable amount ofhandling before the covering bulb is sealed on. The present invention isdesigned to overcome these difiiculties. and to greatly accelerateproduction.

This and other objects will appear from the following description andthe accompanyin drawings illustrating one embodiment the invention, inwhich Fig. 1 is a side elevational view of the device, a gas retainingvessel being shown in association therewith and partially broken away toexpose some of the working parts;

50 Fig. 2is a fragmentary plan view of the device;

Fig. 3 is an end'elevational view thereof,

' shown partially in. section;

Fig. 4: is a detailed view, partially. in sec- 55 tion, of a mercurycontainer disclosing the position of the plunger therein when thefilament tray is removed, and

.Fig. 5 is a circuit diagram including the lamp filaments.

Referring to the drawings wherein like numerals designate similar partsthroughout the several views, it will be observed that this device iscomprised mainly of two cooperating units, one a lower stationary unitdesignated generally by the numeral 10, and the other an upper movableunit similarly referred to by the numeral 11, designed to be moved intoand out of operative engagement with the stationary unit as willhereinafter appear. The stationary unit includes an elongated base plate12 constructed of insulating material and supported at each end byshoulders provided at the lower portions of a pair of vertical pins 13mounted upon a suitable base 14. The base plate 12 supports a pluralityof upright cylindrical mercury containers 15 arranged in three rowslongitudinally of the plate and aligned transversely thereof.

These containers 15 which are preferably constructed of iron or othersuitable material not readily amalgamated by mercury, are reduced attheir lower ends, forming a shank 16 and presenting a shoulder 17 (Fig.3) which rests upon the base plate 12 when the shank 16-is fitted into acompanion aperture 18 provided in the base plate. The end of the shank16 extends below the base plate and is threaded to receive a tighteningnut 19, the tightening of said nut against the plate 12 causing thecontainer 15 to be rigidly secured in its upright position. A; secondnut 20 also threaded upon the shank 16, serves to grip a terminal 21 ofa conductor 22 in position between thenut 20 and the tightening nut 19.The containers 15 are bored longitudinally thereof to provide a chamber23 open at its upper end and adapted to retain a supply of mercury 24.or other suitable conducting fluid. A plunger member 25 provided with acentral, restricted passageway 26, is longitudinally slidable within thechamber 23. Referring to Fig. 4. it will-be noted that the plunger 25will float upon the surface of the mercury 24 with a portion of themercury reaching upwardly into the lower end of the passageway 26, andit 'will be clear that pressure applied at the upper. end of the plunger25 W11]. result in forcing the mercury within the passageway 26 to ahigher level. When the unit 11 is disassociated from the stationary unit10, the buoyancy of the mercury will maintain the plungers 25 at auniform height, with the upper end surfaces thereof within a commonhorizontal plane.

The unit 11 includes a channel-like tray 27, the web thereof having aplurality of insulating bushings 28 fitted therein. These bushings,which are provided with central openings 29, project slightly below theweb of the tray and are arranged in a manner corresponding to thealignment of the containers 15 mounted upon the base plate 12, eachbushing being designed for operative engagement with the upper surfaceof a companion plunger 25. Medially of each inner and outer bushing isan aperture 30, designed to position a lamp stem 31 (Fig. 3) placedtherein. Openings 32 formed at each end of the tray 27 register with theupper reduced extremities of the pins 13 mounted upon the base 14. Thesepins 13, cooperating with the openings 32, facilitate the guiding andpositionin of the unit 11 as it is carried into operatlve engagementwith the unit 10.

Each glass lamp stem 31 is formed with a depending tube 23, a tungstenfilament. 34 being mounted or embedded in the upper end of the stem,said filament having a pair of lead-in terminals 35 disposed downwardlyand outwardly therefrom. When filaments are ready to be treated, in amanner about to be described, the depending tube 33 of each lamp stem 31is inserted in its respective aperture 30 in the tray 27, the unit-11being at this time disassociated from the stationary unit 10. A ball 36formed in the stem 31 serves to limit the distance-to which the filament34 may be lowered into the aperture 30. When the stem 31 is thuspositioned,

' the extremity of one lead-in terminal 35 will reach into the upper,enlarged part of the opening 29 in one of the outer bushings 28 and theextremity of the other terminal 35 will similarly reach into the upperportion of the opening 29 in one of the inner bushings 28, After thestems 31 have been thus positioned in the apertures 30, the unit 11 isbrought into operative engagement with the-unit 10 by first aligning theopenings 32 in the tray 27 with the upper ends of the pinsv 13 andsubsequently lowering the tray in position. Thelower end of each bushing28' being contemporaneously brought into contact with the upper surfaceof its respective plunger 25 causes the mercury to rise within thepassageway 26. The lowering of the tray 27 .is continued until themercury 24 rises within the opening 29 of the bushings 28 and theextremities of the lead-in terminals 35 of the filaments 34 becomeimmersed in the mercury as shown in Fig. 3. The downward movement of thetray 27 is upward displacement of the tray. 4

The circuit diagram shown in Fig. 5 represents a conventional three-wiresystem wlth a sultable source of current supply 39 and a convenientlypositioned circuit closing switch 40, the conductor 22 which connectsthe inner row of container shanks 16 serving as a common return wire.When the lead-111 terminals 35 are immersed in the mercury 24 contained.w ithin the bushings 28, as heretofore described, the filaments 34 arethen connected in parallel with the inner or common conductor 22 and oneof the outer conductors through the medium of the containers 15 and themercury 24 contained therein.

'After the unit 11 has been carried into association with the unit 10and the filaments 34 positioned in circuit closing relation with respectto the contained mercury, as described, the units are covered by asuitable gas retaining vessel 41 (Fig. 1) s A supply of hydrogen gas isadmitted into the vessel 41 through an opening 42 provided at the topthereof. The switch 40 is then closed instantaneously, with the resultthat the fila ments are energized or flashed within the atmosphere ofhydrogen and the complete deoxidation of the tungsten filament effected.

Although reference has been made in the specification to the use of thisinvention in connection with one step in the process of lampmanufacturing, it will be obvious that the invention may be employed togreat ad- Vantage in various other steps wherein it becomes necessary toenergize the filaments for the purpose of treatment or testing.

It is obvious'that changes in the specific form of the invention, asherein described, may be made within the scope of what is claimedwithout departing from the spirit thereof,

. What is claimed is:

1. A contact device designed to complete an electric circuit through acurrent conducting ele1nent,said device including a container, a currentconducting fluid within the container, a support for a currentconducting element, and a plunger mechanism for displacing the fluidvertically within the container to affect the electric circuit inresponse to relative movement between the support and the container.

2. A contact device designed to complete an electric circuit through acurrent conducting element, said device including a container, a currentconducting fluid within the container, a support for a currentconducting element, a plunger member slidable in the container, and apassageway in the plunger to permit of variations in the level of thecurrent conducting fluid occasioned by relative sliding movements of theplun er member within the container, and means or receiving fluidelevated within the passageway in a position readily accessible to asupported current conducting element.

3. A multiple contact device designed to complete electric circuits,said device including a plurality of containers, current conductingfluid in the containers, a member designed to support a plurality ofmetallic elements, and a plunger mechanism for displacing the conductingfluid from within the containers upon the movement of said member intoelectrical contact with the metallic elements simultaneously.

4. A multiple contact device designed to complete electric circuits,said device including .a plurality of containers, current conductingfluid in the containers, a member designed to support a plurality ofcurrent conducting filaments having free terminals, and means fordisplacing the conducting fluid from within the containers intoelectrical contact with terminals of the filaments simultaneously withthe movement of said supporting member.

5. A contact device designed to com lete an electric circuit through acurrent con ucting element, said device including a contamer, a currentconducting fluid within the container, a support for a currentconducting electrical contact with the terminal of the filament inresponse to the relative movement between the supporting member and thecontainer.

7. A contact device designed to complete an electric circuit through acurrent conducting element, said device including a container, a currentconducting fluid in the container, a support for the current conductin 1element, a metallic plunger having a centr passageway verticallyslidable within the container, and an insulating member on the supportfor engagement with the plunger adapted to receive a terminal of asupported element and fluid from the plunger passageway in response torelative movement be tween the plunger and the container.

In Witness whereof, I hereunto subscribe my name this 29th day ofOctober A. D.,

EDWARD VICTOR SUNDT

